A bro culture is often compared to a college frat house culture – hard-partying, amoral, reckless, sexist, and unruly (as portrayed in movies like Animal House and Slackers – when all else fails cheat). Dan Lyon, author of Disrupted: My Misadventure in the Startup Bubble characterizes bro culture as one in which the point is to get away with whatever you can.

There is no single definition for a bro culture, but let me try and sum up its latest manifestation: An aggressively masculine business culture – primarily associated with overconfident, but inexperienced, young white males (notably in the tech/venture capital industry) whose aim is to win at any cost.

Speaking of Uber’s ex-CEO, Fortune Executive Editor Adam Lashinsky said that Kalanick’s flying in the face of convention (as well as regulations and the law) style was initially an asset, but ultimately became a horrible liability. Bro culture tends to be brash, arrogant, obnoxious, and uncompromising, and while there might be short-term victories, the culture is not sustainable.

Capitalism is based on ongoing disruption to the norm, but a disruptive idea usually requires a seasoned and steady hand to guide it through the turbulent social and political landscape, e.g. Eric Schmidt at Google. Kirk Hanson with the Markkula Center for Applied Ethics at Santa Clara University commented recently, “I expect that Uber will be a classic case study in five years in which we look at how a startup can go wrong if the CEO visionary is not controlled and given adult supervision.”

A few years ago, I described leadership as having three main components: Vision, Strategy, and Influence. We might award Kalanick high marks for vision, and OK marks for strategy, but his style undercut his influence outside of the bro culture. Kalanick offended politicians, his drivers, customers, and his main US competitor, Lyft (he hailed and then cancelled thousands of rides from its drivers which he described later as a recruiting tactic). A video of Kalanick berating one of his own drivers leaked out to which he responded, “I must fundamentally change as a leader and grow up.” A hopeful sign for his future, perhaps.

Ultimately, Kalanick’s bro culture was exposed and challenged by one of the most offended groups of all – women. Susan Fowler, a former Uber engineer accused the company of sexual harassment, and more followed. Bro cultures do hire women, but they tend to be disrespected and marginalized.

A bro culture might not characterize a whole company, but a segment, and it might not be restricted to young white men. It is also not limited to the tech industry. I have personally experienced bro culture in the financial industry. I don’t think it is too farfetched to say that the economic collapse of 2008 was in part the product of reckless bro cultures in banking.

Bro cultures lack diversity, and that is a good place to start bringing them under control.